The veterans on the Minnesota Vikings defense are still significant contributors.
Jared Allen, Chad Greenway, Kevin Williams and Antoine Winfield continue to make their mark.
But the source of the improvement this season can be traced straight to the young guys.
Rookie Josh Robinson, who has the team's only interception, has provided an obvious upgrade at cornerback in the nickel package. Jasper Brinkley has taken over at middle linebacker without much trouble. Another first-time starter, Letroy Guion, has played well at nose tackle.
Then there's utility lineman Everson Griffen, emerging as a secret pass rushing weapon in his third season, and rookie strong safety Harrison Smith, who has given the Vikings the hard-hitting, smart, ball-hawking player they haven't had in years at that position.